..As Pumiliornis does not belong to any of the modern groups of flower-visiting birds, the origin of ornithophily in some angiosperm lineages may have predated that of their extant avian pollinators. ..

Earliest and first Northern Hemispheric hoatzin fossils substantiate Old World origin of a "Neotropic endemic"

..Their regular and symmetrical arrangement over most of the external vertebral surface indicates a systemic disorder caused by factors that do not affect extant birds, such as especially high-dosed phytohormones or extinct pathogens...

..Occurrence of stem lineage Grues in the Lower Oligocene of Europe is in concordance with the fact that there is no evidence for the presence of crown group members of modern avian "families" in pre-Oligocene fossil deposits...